I have two tables. Table1, Table2. I have to get names from Table2 based on some other id's which are common in Table1 and Table2. I have to update Table1 and field name is "Name"
Table1:
id | Name
-------------
a,b,c |
Table2:
id | Name
------------
a | dinesh
b | suresh
c | ganesh
Output in Table1:
Id | Name
-------------------------------
a,b,c | dinesh, suresh, ganesh
Since you show no attempt at solving this yourself, I will assume you just need to be pointed in the direction of a solution.
One way to approach this is to use a string-split function (there is one built in to SS 2017, but previous versions you had to create one--there are plenty available on this site if you google).
This function will return a table with one row for each of the comma separated values in Table1. Then you JOIN that to Table2 to get the name and use that to build a comma-separated string with a group-concat function (also built in to SS 2017, but with plenty of examples here about how to do this with earlier versions).
Once you have gotten those values SELECTed, it's a simple matter to generate an UPDATE from that SELECT and update Table1 with the comma-separated string.
Related
Please who can help with this scenario?
I have two tables, both they have a common column ID, and Table 1 has a column Title. Normally I should update the content of this Title column for some ID, but since the table was already in use somewhere else, it wasn't a good idea to change data directly in Table 1.
That's why I created a new table table 2, which hold only the Title that must be changed associated with these ID that must be changed.
Now I am trying to get these updated titles from table 2, when there is a matching ID in table 1, otherwise show only the contents of table 1.
The result should be something like that but without using If statements.
__ID__ Title
| | | |
| | | |
You can use LEFT OUTER JOIN to this new table and COALESCE() function to say "If there is data in the new table, use it, otherwise use the data in the existing table" . Something like:
SELECT t1.id, COALESCE(t2.title, t1.title) as title
FROM t1
LEFT OUTER JOIN t2 ON t1.id = t2.id;
Let's say I have a table:
| key1 | key2 | value |
+------+------+-------+
| 1 | 1 | 1337 |
| 1 | 2 | 6545 |
| 2 | 1 | 213 |
| 3 | 1 | 131 |
What I would like to do is traverse this table row by row, then using the key two values in further queries (all other tables contain the unique combination of these two keys + other data)
How do I do this kind of thing in SQL?
EDIT: I would want to extract key1, key2 from row 1 (1,1) then do a query on it, which would result in a number.
Then I would move to the second row, an identical query which would again result in a number.
All of these numbers would be then inserted into a pre-prepared view.
EDIT2: I need to traverse it because the specific use of my database.
It is a database of planets which contains sectors (the keys are the IDs of these two). All of these sectors contain resources, turrets and walls.
The table I have in my post is an example of table of sectors, with the value being enemy force.
Table of resources, turrets etc. contain these two keys so they are linked to and only to a specific sector.
I need to go row by row so I can use this keys to select only specific resources/turrets/walls from my tables, aggregate them and then subtract them from the value in my sector table. Resulting number would then be inserted into a pre-prepared view (again, into the row which matches the combination of my two keys)
This sounds like a correlated subquery or lateral join. You don't have that much explanation, but something like this:
select t1.*, t2.*
from table1 t1 cross join lateral
(select . . .
from table2 t2 . . .
where t2.key1 = t1.key1 and t2.key2 = t1.key2
) t2
You are not clear on what the second query looks like. The where clause is called a correlation clause. It connects the subquery to the outer query. A correlation clause is not strictly needed for this to work.
The columns from the outer query can be used elsewhere in the subquery. I am just assuming that an equality condition connects the two (lacking other information).
In one table, I have a column that contains a letter and another that contains a letter of a later alphabetical order. Like 'A' for the former and 'R' for the latter for example. I want to use these two columns in a Between operator to search for words in another table that starts a letter from the first column and ends with a letter from the second. So in my example, 'Air' would fit this requirement. The problem is I also need to add these two columns to results, so that for my example, the query would return 'Air' with 'A' and 'R' from the other table as two columns in my results. Sorry I can't be more explicit as the data is sensitive.
Based on what you have described here is one way to get the output.
create table t(id int, start_letter varchar(1), end_letter varchar(1));
create table search_data(words varchar(50))
insert into t values(1,'A','R')
begin
insert into search_data values('Air');
insert into search_data values('Amour');
insert into search_data values('Arogant');
end;
select *
from search_data a
join t b
on lower(substring(a.words,1,1))=lower(b.start_letter)
and lower(substring(reverse(a.words),1,1))=lower(b.end_letter)
+-------+----+--------------+------------+
| words | id | start_letter | end_letter |
+-------+----+--------------+------------+
| Air | 1 | A | R |
| Amour | 1 | A | R |
+-------+----+--------------+------------+
db fiddle link
https://dbfiddle.uk/?rdbms=sqlserver_2019&fiddle=82cf80f4b76cb740ae56db8f236bfd46
I am currently rebuilding a messy Access Database and I entcountered the following problem:
I've got a Table of facilities which contain a row called district. Those Rows contain a number linked to another table which just contains the numbers and names of districts. I added a lookup Column with the Name of the district displayed.
I now want to change the new column for every row depending on the data in the old row.
Facilities
NAME|..|DISTRICT_OLD
A |..| 1
B |..| 2
C |..| 1
...
DISTRICTS
ID|NAME
1 |EAST
2 |WEST
...
I would like something like the following:
Facilities
NAME|..|DISTRICT_OLD|DISTRICT
A |..| 1|EAST
B |..| 2|WEST
C |..| 1|EAST
...
The District Field (lookup) gets its Data like follows SELECT [DISTRICTS].ID, [DISTRICTS].NAME FROM DISTRICTS ORDER BY [NAME];
(Thanks to Gordon Linoff) I could get the query but I do now struggle with the insert. I can get the Data I want:
SELECT [DISTRICTS].NAME FROM Facilities INNER JOIN DISTRICTS ON Facilities.DISTRICT_OLD = [DISTRICTS].ID;
If I try to INSERT INTO Facilities(DISTRICT) It says Typerror.
How can I modify the data to be compatible with a lookup column?
I guess I need to select the ID as well which isnt't a problem but then the error says to many columns.
I hope I haven't mistaken any names, my Access isn't running the english language.
Can you help me?
Fabian
Lookup columns are number (long integer)
with a relational database, you only need the single column containing the ID (as you always lookup the district.name with a query) so:
INSERT INTO Facilities(DISTRICT) SELECT 4
where 4 is the ID of the record in the lookup table that you want, or better still:
INSERT INTO Facilities(DISTRICT)
SELECT ID FROM DISTRICTS
where District.Name = "Name you want the ID for"
This is staight forward I believe:
I have a table with 30,000 rows. When I SELECT DISTINCT 'location' FROM myTable it returns 21,000 rows, about what I'd expect, but it only returns that one column.
What I want is to move those to a new table, but the whole row for each match.
My best guess is something like SELECT * from (SELECT DISTINCT 'location' FROM myTable) or something like that, but it says I have a vague syntax error.
Is there a good way to grab the rest of each DISTINCT row and move it to a new table all in one go?
SELECT * FROM myTable GROUP BY `location`
or if you want to move to another table
CREATE TABLE foo AS SELECT * FROM myTable GROUP BY `location`
Distinct means for the entire row returned. So you can simply use
SELECT DISTINCT * FROM myTable GROUP BY 'location'
Using Distinct on a single column doesn't make a lot of sense. Let's say I have the following simple set
-id- -location-
1 store
2 store
3 home
if there were some sort of query that returned all columns, but just distinct on location, which row would be returned? 1 or 2? Should it just pick one at random? Because of this, DISTINCT works for all columns in the result set returned.
Well, first you need to decide what you really want returned.
The problem is that, presumably, for some of the location values in your table there are different values in the other columns even when the location value is the same:
Location OtherCol StillOtherCol
Place1 1 Fred
Place1 89 Fred
Place1 1 Joe
In that case, which of the three rows do you want to select? When you talk about a DISTINCT Location, you're condensing those three rows of different data into a single row, there's no meaning to moving the original rows from the original table into a new table since those original rows no longer exist in your DISTINCT result set. (If all the other columns are always the same for a given Location, your problem is easier: Just SELECT DISTINCT * FROM YourTable).
If you don't care which values come from the other columns you can use a (bad, IMHO) MySQL extension to SQL and do:
SELECT * FROM YourTable GROUP BY Location
which will give a result set with one row per location and values for the other columns derived from the original data in an undefined fashion.
Multiple rows with identical values in all columns don't have any sense. OK - the question might be a way to correct exactly that situation.
Considering this table, with id being the PK:
kram=# select * from foba;
id | no | name
----+----+---------------
2 | 1 | a
3 | 1 | b
4 | 2 | c
5 | 2 | a,b,c,d,e,f,g
you may extract a sample for every single no (:=location) by grouping over that column, and selecting the row with minimum PK (for example):
SELECT * FROM foba WHERE id IN (SELECT min (id) FROM foba GROUP BY no);
id | no | name
----+----+------
2 | 1 | a
4 | 2 | c